GLOSSARY OF STATISTICAL TERMS
Confidence interval
a specified interval, with the sample statistic at the centre, within which the corresponding population value is said to lie with a given level of confidence.
Data Item
the smallest piece of information that can be obtained from a survey or census.
Data Set
data collected for a particular study. A data set represents a collection of elements; and for each element, information on one or more characteristics is included.
Distribution
pattern of observation values in a data set.
Estimate
information about a population derived from a sample of units from that population.
Frequency
number of times an observation occurs in a data set.
Non-sampling error
inaccuracies that occur due to reporting imperfections by respondents and interviewers, and errors made in coding and processing data. These errors can occur whether information is derived from a sample or census.
Observation
a single piece of data about a variable.
Sampling error
difference between an estimate derived from a sample survey and the true value that would result if a census of the whole population was taken.
Unit
an entity about which information is being collected.
Variables
mutually exclusive characteristics such as sex, age, and employment status. Surveys often aim to describe the distribution of characteristics comprising a variable in a population.